Vulnerability Assessment & Network Security Forums

If through a vulnerability assessment, a network security issue is detected for the vulnerability below, applying the appropriate security patches in a timely matter is very important. If you have detected that your system has already been compromised, following CERT's Network Security recovery document will assist with recommended steps for system recovery.

Home >> Browse Vulnerability Assessment Database >> Firewalls >> Weak Initial Sequence Number

Vulnerability Assessment Details

Weak Initial Sequence Number

Vulnerability Assessment Summary
checks for ISN

Detailed Explanation for this Vulnerability Assessment

The remote host seems to generate Initial Sequence Numbers (ISN) in a weak
manner which seems to solely depend on the source and dest port of the TCP
packets.

A possible hacker may exploit this flaw to establish spoofed connections to the
remote host.

The Raptor Firewall and Novell Netware are known to be vulnerable to this
flaw, although other network devices may be vulnerable as well.

Solution :

If you are using a Raptor Firewall, see
http://www.symantec.com/techsupp/bulletin/archive/firewall/082002firewall.html

Otherwise, contact your vendor for a patch.

Reference : http://online.securityfocus.com/archive/1/285729

Network Security Threat Level: High

Networks Security ID: 5387, 8652

Vulnerability Assessment Copyright: This script is Copyright (C) 2002 Renaud Deraison

Cables, Connectors